Avaliação da recuperação da cartilagem articular do tornozelo de ratos após aplicação de um protocolo de alongamento cíclico da musculatura posterior da perna após imobilização
Abstract
Objective: To evaluate the recovery of ankle articular cartilage of rats after applying
unilateral cyclic passive muscle stretching protocol in previously hindlimb immobilization.
Methods: fourty Wistar rats were divided in seven groups: C- control; I- immobilized ; RI-
seven weeks recovery after immobilization; S- Stretched; RS- seven weeks recovery after
stretch; IS- immobilized and stretched; ISR- immobilized-stretched and seven weeks
recovery. The left ankle joint from the groups I, RI, IS and ISR were immobilized for 4 week.
In the muscle stretching protocol the left ankle joint was mantained manually full dorsal
flexed, 10 times for 60s with a 30s rest between each stretch, seven days a week for three
weeks, to stretch the ankle plantar flexors muscle of groups IS, S, ISR and SR. The right
ankle joint were free to move. After this intervention period, the rats of RI, RS, ISR groups
was free to move for recovery during seven weeks. At the end of experiment, the animals
were sacrified and the ankles were removed, decalcified and processed in paraffin, and
stainded with Hematoxilin-Eosin. Two blinded observers evaluated morphologic changes by
Mankin score. A morphometric study was carried out using a hand count of chondrocytes
cells and cartilage thickness measuraments.
Results: No changes in all thickness was found. The C group had the calcified cartilage
bigger than the other groups. The IS group had in your treated limb more cells and clonings
than the IR group, and in the non-treated more cell and clonings than the C, RI and SR
groups.
Conclusions: The muscle stretching after immobilization increases the number of
chondrocytes and the presence of cloning, and when free movement is allowed during the
recovery period from immobilization, the chondrocyte characteristics tend to return to those
present before immobilization, suggesting better cellular recovery